<!DOCTYPE html>
<html reftest-async-scroll
      reftest-displayport-x="0" reftest-displayport-y="0"
      reftest-displayport-w="800" reftest-displayport-h="2000"
      reftest-async-scroll-x="0" reftest-async-scroll-y="100">
<style>
body {
  margin: 0;
  height: 4000px;
  overflow: hidden;
}
div {
  background: blue;
  width: 200px;
  height: 200px;
  margin-top: 400px;
  position: sticky;
  bottom: 100px;
}
</style>
<div></div>
